<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<link rel="stylesheet" type="text/css" href="css/style.css"/>
		<style type="text/css">
			.box1{

			}
			.box-item{
				flex-basis: 100%;
			}
		</style>
	</head>
	<body>
		<div class="box box1">
			<div class="box-item">1</div>
			<div class="box-item">2</div>
			<div class="box-item">3</div>

		</div>
	</body>
</html>
